Isopropyl Alcohol - 70% or 91%?

FelixDeCat

Lifer
Aug 4, 2000
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So Ive been a user of 91% Isopropyl (rubbing) Alcohol for various purposes for several years now and recently made the mistake of purchasing 70%. I had forgotten how weak this variety was and was disappointed when a strong aroma did not pierce of air when I opened the bottle. Furthermore, Im afraid that because it wont leave extremely dry skin behind that it is in fact not really "working". I have to see it to believe it! And I want to see the bodies of dead germs everywhere including collateral damage to supple skin surface.

Does it matter to you either way what type of alcohol you use? Or are you an indifferent middle of the road type, just going through life in a happy-go-lucky fashion not really caring if the job was done or not?
 

Leros

Lifer
Jul 11, 2004
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I've always used 91% for cleaning thermal compound off my CPUs. I don't use rubbing alcohol for medical reasons too much.
 

FelixDeCat

Lifer
Aug 4, 2000
30,599
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Originally posted by: Leros
I've always used 91% for cleaning thermal compound off my CPUs. I don't use rubbing alcohol for medical reasons too much.

Ive used it for that reason too. Unfortunately now I have to use the 70% bottle I accidently purchased the other day. No sense in pouring $1.49 down the drain. :(
 

Cogman

Lifer
Sep 19, 2000
10,284
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For medical stuff, it really doesn't matter. 70% will kill 99.99% of everything on the skin.

The only reason to go with 91% is if you are cleaning something that can't get wet.
 

FelixDeCat

Lifer
Aug 4, 2000
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Originally posted by: Cogman
For medical stuff, it really doesn't matter. 70% will kill 99.99% of everything on the skin.

The only reason to go with 91% is if you are cleaning something that can't get wet.

Hmmm.....what are some things you cant get wet?
 

Cogman

Lifer
Sep 19, 2000
10,284
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Originally posted by: FelixDeKat
Originally posted by: Cogman
For medical stuff, it really doesn't matter. 70% will kill 99.99% of everything on the skin.

The only reason to go with 91% is if you are cleaning something that can't get wet.

Hmmm.....what are some things you cant get wet?

Electronic circuit boards. Anything that rusts, There could be other things, but those are the two that comes off the top of my head.
 

Vinny N

Platinum Member
Feb 13, 2000
2,277
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Best I ever used was 99% from a chem student :p

Of course, they suggested that I use their "water" (aka acetone).

I was even more wowed. As long it's not plastic that is going to be melted away acetone is awesome for cleaning cpus and other goodies :p
 

FelixDeCat

Lifer
Aug 4, 2000
30,599
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Originally posted by: Vinny N
Best I ever used was 99% from a chem student :p

Of course, they suggested that I use their "water" (aka acetone).

I was even more wowed. As long it's not plastic that is going to be melted away acetone is awesome for cleaning cpus and other goodies :p

Thanks for the suggestion! But I prefer to biosynthesize small amounts in my own human body. :shocked:
 

kami333

Diamond Member
Dec 12, 2001
5,110
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Originally posted by: FelixDeKat
So Ive been a user of 91% Isopropyl (rubbing) Alcohol for various purposes for several years now and recently made the mistake of purchasing 70%. I had forgotten how weak this variety was and was disappointed when a strong aroma did not pierce of air when I opened the bottle. Furthermore, Im afraid that because it wont leave extremely dry skin behind that it is in fact not really "working". I have to see it to believe it! And I want to see the bodies of dead germs everywhere including collateral damage to supple skin surface.

Does it matter to you either way what type of alcohol you use? Or are you an indifferent middle of the road type, just going through life in a happy-go-lucky fashion not really caring if the job was done or not?

Actually 70% isopropyl is a better disinfectant. Alcohol works as a disinfectant by denaturing proteins, a small amount of water makes it more efficient.
 

Bill Brasky

Diamond Member
May 18, 2006
4,324
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I use ethanol to do cleaning in the lab when I'm feeling lazy and don't want to use proper detergent. But usually alcohol is reserved for computer parts. 91%.
 

0roo0roo

No Lifer
Sep 21, 2002
64,795
84
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i use 70-91 for cleaning stuff like hs paste. 50% dilute to spray on screens for cleaning.
so what do you rub it on your skin for anyways? whats the point.
 

DrPizza

Administrator Elite Member Goat Whisperer
Mar 5, 2001
49,601
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www.slatebrookfarm.com
Originally posted by: Cogman
For medical stuff, it really doesn't matter. 70% will kill 99.99% of everything on the skin.

The only reason to go with 91% is if you are cleaning something that can't get wet.

So how many bacteria are there if 0.01% survives? And, if you start with 2000 bacteria that double every 15 minutes... How long til it didn't matter in the first place? :p ;)
 

DanTMWTMP

Lifer
Oct 7, 2001
15,908
19
81
LOL @ thread. But there's quite a bit of cool info too.

Originally posted by: Cogman
For medical stuff, it really doesn't matter. 70% will kill 99.99% of everything on the skin.

The only reason to go with 91% is if you are cleaning something that can't get wet.

Originally posted by: kami333

Actually 70% isopropyl is a better disinfectant. Alcohol works as a disinfectant by denaturing proteins, a small amount of water makes it more efficient.

That's interesting. I never knew.


I've always got 91% to clean my balls and, sometimes, my arse (I had a cut down there once. I figured, that having my dump cover up the wound wasn't a good idea, and it's a good idea to disinfect it). The burn was incredible. I doubled up in pain on the floor, but never felt so refreshed, knowing all those bacteria was dying and screaming.
 

her209

No Lifer
Oct 11, 2000
56,336
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Originally posted by: DanTMWTMP
That's interesting. I never knew.

I've always got 91% to clean my balls and, sometimes, my arse (I had a cut down there once. I figured, that having my dump cover up the wound wasn't a good idea, and it's a good idea to disinfect it). The burn was incredible. I doubled up in pain on the floor, but never felt so refreshed, knowing all those bacteria was dying and screaming.
Wow. Too much information!
 

FelixDeCat

Lifer
Aug 4, 2000
30,599
2,586
126
Originally posted by: her209
Originally posted by: DanTMWTMP
That's interesting. I never knew.

I've always got 91% to clean my balls and, sometimes, my arse (I had a cut down there once. I figured, that having my dump cover up the wound wasn't a good idea, and it's a good idea to disinfect it). The burn was incredible. I doubled up in pain on the floor, but never felt so refreshed, knowing all those bacteria was dying and screaming.
Wow. Too much information!

My thoughts exactly. :laugh:

But Ive had to apply some to the 'cavity' as well, and trust me the pain is incredible but the feeling afterwards is quite refreshing. :)
 

FelixDeCat

Lifer
Aug 4, 2000
30,599
2,586
126
Originally posted by: DrPizza
Originally posted by: Cogman
For medical stuff, it really doesn't matter. 70% will kill 99.99% of everything on the skin.

The only reason to go with 91% is if you are cleaning something that can't get wet.

So how many bacteria are there if 0.01% survives? And, if you start with 2000 bacteria that double every 15 minutes... How long til it didn't matter in the first place? :p ;)

I am glad we agree on this point. I have no sympathy for bacteria. I dont care what kind of life they led up to that point. I dont care what their philosphical point of view is. I dont even care where they were born.

They must die. They must die now.
 

Kobota

Senior member
Aug 5, 2003
529
11
81
Originally posted by: FelixDeKat
Originally posted by: Cogman
For medical stuff, it really doesn't matter. 70% will kill 99.99% of everything on the skin.

The only reason to go with 91% is if you are cleaning something that can't get wet.

Hmmm.....what are some things you cant get wet?

well there was this girl, but i was drunk, i did my best:eek:
 

FelixDeCat

Lifer
Aug 4, 2000
30,599
2,586
126
Originally posted by: Kobota
Originally posted by: FelixDeKat
Originally posted by: Cogman
For medical stuff, it really doesn't matter. 70% will kill 99.99% of everything on the skin.

The only reason to go with 91% is if you are cleaning something that can't get wet.

Hmmm.....what are some things you cant get wet?

well there was this girl, but i was drunk, i did my best:eek:

Was her name Ellen?
 

0roo0roo

No Lifer
Sep 21, 2002
64,795
84
91
Originally posted by: FelixDeKat
Originally posted by: Cogman
For medical stuff, it really doesn't matter. 70% will kill 99.99% of everything on the skin.

The only reason to go with 91% is if you are cleaning something that can't get wet.

Hmmm.....what are some things you cant get wet?

mermaids?